Seat mounts and harness

Section 6:2 in the general rules second sentence." The drivers seat must be supported on the bottom and back by the frame or crossmember. Except as noted in sfi specs, seats must be bolted with four bolts on bottom and one in the rear into crossbar; all bolts must go into frame or cross braces. "

Again, I believe this is only referring to vehicles that have a roll bar. What car has a 'cross member' that you can attach something to? None, that I am aware of because they are referring to a roll bar. The rules in section 6.2 pertain to cars competing in classes that require a roll bar. A 12 second car does not require a roll bar so you would not be required to adhere to those rules. In plain English - if you had a roll bar or cage, you'd need to mount the seat per the rules.

Now in a pickup there is one small crossmember maybe an inch and half wide below the floor closer to the door than I like. Now since I am the one asking the question that in no way was asking about expired belts, how can I legally mount my seat in the pick up?

I realize you have an aftermarket seat/mounts so again, you need to interpret the rules as best as you can. It is a grey area because stock configuration is allowed but when you start modifying stuff then you open yourself up to interpretation. Therefore, if you have no roll bar, there is no proper way to adhere to the rules. Perhaps you might want to rethink your seat, maybe go back to a stock seat for now to avoid the hassle.

As far as my seat belt question the book says. All harness sections must be mounted to the frame, crossmember, or reinforced mounting,....
In no way does the rules say I cannot mount the shoulder belts to the floor where the lap belts are mounted. What qualifies as reinforced mounting? Is fender washers considered reinforced?

Again, I would not mount a 5 point harness to the floor. The rear straps need to be at a certain angle which usually coincide with the height of the main hoop crossbar. In your case with no bar, that would likely be through the back of the cab. There is a reason a roll bar is measured with you in the car so whoever fabs it knows where to put the cross bar and how high your shoulders are when you are sitting in driving position.